Taper pin driver having a hook shaped end with a recess



March 1967 H. R. GOODWIN ETAL 3,307,250

TAPER PIN DRIVER HAVING A HOOK SHAPED END WITH A RECESS Filed Dec. 21, 1965 FIG.

I NVENTORfi- HARVEY RGOODWEN RSBAUGH TTORNEY United States Patent ()fiice 3,307,250 Patented Mar. 7, 1967 3,307,250 TAPER PIN DRIVER HAVING A HOOK SHAPED END WITH A RECESS Harvey Richard Goodwin, Burbank, and Robert B.

Mothersbaugh, Simi, Calif., assignors to General Precision, Inc., a corporation of Delaware Filed Dec. 21, 1965, Ser. No. 515,342 Claims. (Cl. 29-257) This invention relates to hand tools, and more particularly to a novel and improved driver for inserting or removing pin fasteners used for connecting mechanical members to drive shafts.

In the assembly of precision mechanical equipment which incorporated gearing, it is common practice to connect a gear to a drive shaft by forcing a taper pin diametrically through the gear hub and drive shaft. In the event that it is necessary to remove a taper pin when the drive shaft and gear are removable from the assembly, it is generally a simple process to remove the shaft with the gear attached, place the hub of the gear in a V block, and drive out the pin with a hand punch.

In the event it is necessary to remove a taper pin without removing the drive shaft from the mechanical assembly, it is difficult or impossible to use a V block, and the use of the punch without some backing means to remove the taper pin may cause a serious misalignment of the drive shaft and a consequent severe damage to the mechanical assembly.

This invention provides a new and improved means for removing or inserting taper pins, roll pins, or the like, and is particularly valuable where the drive shaft and the connecting mechanical member are deep within a mechanical assembly where the drive shaft should not or cannot be removed. The tool comprises a replaceable hook-shaped jaw having a configuration that conforms to the hub of the gear, and a replaceable drive pin extending into the hook and having an end configuration adapted to mate with the end of the taper pin which fastens the hub. The drive pin of the tool is then urged further toward the hook-shaped jaw by the action of a drive screw which is threaded in the housing to which the jaw is connected. The housing may be provided with spare jaw members adapted to replace the jaw member in use so as to fit hubs of various diameters and, similarly, with extra drive pins to replace the drive pins in use so as to fit various sizes and types of taper pins. As used in this specification the term taper pins is intended to include taper pins, roll pins, headless pins and other fastening devices used in a manner similar to taper pins.

An important feature of the invention is that the housing, the replaceable jaw member and drive pins are found so interrelated that the jaw member and drive pin may be used interchangeably, that is, as replacement members depending upon the size of the hub or the taper pins upon which the tool is to be used.

One object of this invention is to provide a portable hand tool which is capable of inserting or removing taper pins without removing the associated mechanical part from the mechanical assembly.

Other objects will become apparent from the following detailed description when taken into consideration with the drawings, in which:

FIGURE 1 is a perspective view of a preferred embodiment of the invention,

FIGURE 2 is a sectional view of the embodiment illustrated in FIGURE 1, and

FIGURE 3 is an enlarged illustration of the invention, engaging a taper pin and hub.

In FIGURE 1, which shows a preferred embodiment of the invention, the taper pin driver is shown with a gear 10 which is connected to a drive shaft 12 by a taper pin 13 which is fitted into a taper hole extending diametrically through hub 14 and drive shaft 12.

The taper pin 13 Within hub 14 and shaft 12 may be removed or inserted by the action of the drive pin 16 which has the tip 18 which is tapered and shaped to fit within the taper pin hole. Drive pin 16 is slidably mounted within jaw member 20 which is provided with an arcuate shaped hook 22, which is adapted to conform to the configuration of hub 14, as shown in FIGURES 1 and 3. Jaw member 20 may be of any suitable length and should be of a strong rigid material that is sufiiciently thin so that the drive pin 16 may properly engage the taper pin hole in hub 14 without interference from the gear body. Hook 22 is provided with a relief slot 24 which is cut in the center of hook 22 and upon the longitudinal center line of drive pin 16. Relief slot 24 must be of suitable size so that when a taper pin is removed by the urging of drive pin 16, at least a portion of the taper pin may pass into slot 24.

As indicated above, drive pin 16 is slidably mounted within a hole 26 extending through jaw member 20. Drive pin 16 can thus be urged through hole 26 so that drive pin tip 18 may insert or remove a taper pin. Jaw member 20 is detachably connected to a housing 28 by screws 30. Housing 28 has a threaded bore 32 extending therethrough which is provided with a threaded screw member 34 which may, if desired, be equipped with a T handle 36 for hand operation of the screw member. Threaded bore 32 is positioned within housing 28 so that the center line of bore 32 and the center line of hole 26 in jaw member 20 are coaxial.

As shown in FIGURE 2, the end of screw member 34 opposite T handle 36 and within housing 28 is adapted to mate with the end of drive pin 16 that is opposite drive pin tip 18. Screw member 34 is provided with an axial hole 38 having a diameter slightly in excess of the diameter of drive pin 16 so that drive pin 16 may freely rotate within axial hole 38. In order to prevent friction between drive pin 16 and screw member 34, and in order to prevent the rotation of screw member 34 from transmitting rotation to drive pin 16, a ball bearing 40 is inserted in coaxial hole 38 to provide a single point bearing between drive pin 16 and screw member 34.

Because of the single point bearing action between drive pin 16 and screw member 34, it is apparent that unscrewing or withdrawing screw member 34 from its threaded bore 32 will not withdraw drive pin 16 away from the hook 22 in jaw member 20. In order to provide a means for withdrawal of drive pin 16, a helical spring 42 is inserted in threaded bore 32 to exert force between the end of jaw member 20 which is connected to housing 28, and a cylindrical hub 44 which is rigidly connected to drive pin 16 near the end which is mated to screw member 34. In addition to providing a surface for spring 42 to act upon, hub 44 also restricts or limits the movement of pin 16 toward hook 22. Cylindrical hub 44 should have an external diameter suitable to provide sliding action Within threaded bore 32 and an internal diameter suitable to provide a press fit on drive pin 16. If desired, hub 44 may be an integral part of drive pin 16 by either welding hub 44 to the drive pin or by manufacturing hub 44 and drive pin 16 from one piece of material.

Housing 28 may be provided with additional jaw members and drive pins to accommodate taper pins and gear hubs of different sizes. FIGURE 1 illustrates the housing 28 provided with a jaw member 46 having a large hook 48 which is adapted to fit gear hubs of a larger diameter than hub 14 shown in FIGURE 1. Similarly, FIGURE 2 illustrates that additional drive pins 50 may be housed within holes bored through housing 28 and 3 may be retained within those holes by a suitable spring clip 52.

In operation the taper pin drive may be used to insert or remove taper pins in mechanical components that are located deep within a mechanical assembly. Screw member 34 is unscrewed or withdrawn a suitable distance from its threaded bore 32 and the expansion action of helical spring 42 against cylindrical hub 44 will withdraw drive pin 16 away from hook 22 in jaw member 20. J aw member 20 is then inserted into the mechanical assembly and hook 22 is fitted over the hub of the mechanical component, which, for example, is to be removed. Screw member 34 is then screwed into the threaded bore 32 to impart force against drive pin 16 so that tip 18 will mate with the taper pin 13 and urge the pin from the hub. As drive pin 16 urges the taper pin from its hub, the large end of the taper pin will be forced into the relief slot 24, at which time the taper pin is loose in its tapered hole. It should be noted that, because of the action of ball bearing 41 the rotational motion of screw member 34 is not imparted to drive pin 16 so that the only motion of drive pin 16 is along its center line, thus eliminating any grinding action between drive pin tip 18 and the end of the taper pin being removed. Such an absence of grinding action prevents destructive wear of the drive pin tip 18 and the swaging of the taper pin being removed.

If it is necessary to change jaw members to accommodate a different size gear hub, it is only necessary to remove screws 30 and remove jaw member 20 from the drive pin 16 which will remain in position. A jaw member of suitable size may then be inserted over drive pin 16 and securely fastened by screws 30.

If the drive pin 16 is to be changed for one of a different size, screw member 34 is removed from housing 28, the drive pin is removed through threaded bore 32 and the desired drive pin is reinserted through bore 32. For this change of drive pins, jaw member 20 need not be removed.

What is claimed is:

1. A taper pin driver comprising in combination:

(a) a housing having a longitudinal threaded bore extending therethrough,

(b) a screw member in said threaded bore and adapted to be threaded in and out of said threaded bore of said housing,

(c) a replaceable jaw member detachably connected to one end of said housing,

(1) said jaw member being provided with a drive pin hole coaxial with the threaded bore in said housing,

(2) said jaw member having a hook for engaging the hub of a connecting member on a shaft,

(3) said hook being centered upon the axes of the threaded bore in said housing and the drive pin hole in said jaw member,

(4) said hook being provided with a relief slot centered upon the axis of the drive pin hole in said jaw member, and

(d) a drive pin slidably positioned Within the drive pin hole in said jaw member,

(1) said drive pin being shaped at one end to mate with the taper pin and the opposite end adapted to mate with the end of said threaded screw member within said housing.

2. A taper pin driver according to claim 1 wherein said drive pin is provided with a hub within said housing to prevent removal of said pin through said jaw member.

3. A taper pin driver in accordance with claim 1 wherein said drive pin is provided with spring means between said restricting means and the end of said jaw member connected to said housing whereby said drive pin is forced from the hook in said jaw member.

4. A taper pin driver in accordance with claim 1 wherein the end of said screw member which mates with said drive pin is provided with a bearing means.

5. A taper pin driver in accordance with claim 1 wherein the jaw member and drive pins may be used alternatively and respectively with other jaw members and drive pins to perform upon hubs and taper pins of different sizes.

References Cited by the Examiner UNITED STATES PATENTS 186,229 1/ 1877 Casterline M 29-261 1,241,846 10/1917 Grons 29-264 1,610,969 12/ 1926 Robertson 29-270 X 2,797,471 7/ 1957 Hamberger 29-278 X FOREIGN PATENTS 1,037,291 4/ 1953 France.

WILLIAM FELDMAN, Primary Examiner.

M. KRUSE, Examiner. 

1. A TAPER PIN DRIVER COMPRISING IN COMBINATION: (A) A HOUSING HAVING A LONGITUDINAL THREADED BORE EXTENDING THERETHROUGH, (B) A SCREW MEMBER IN SAID THREADED BORE AND ADAPTED TO BE THREADED IN AND OUT OF SAID THREADED BORE OF SAID HOUSING, (C) A RECEPTACLE JAW MEMBER DETACHABLY CONNECTED TO ONE END OF SAID HOUSING, (1) SAID JAW MEMBER BEING PROVIDED WITH A DRIVE PIN HOLE COAXIAL WITH THE THREADED BORE IN SAID HOUSING, (2) SAID JAW MEMBER HAVING A HOOK FOR ENGAGING THE HUB OF A CONNECTING MEMBER ON A SHAFT, 